Test Score Ambiguity

The problem with using test scores to tell us something about a student, teacher, school or community is that there are far too many variables.

Here's a question from the book The Myths of Standardized Tests:

If 85 percent or more the students in your child's classroom or school meet or exceed the proficiency standards, that means: 

a) your child has an exemplary teacher.
b) your school has an exemplary principal.
c) both a and b.
d) your school community is wealthier than average.
e) all, any combination, or none of the above.

While it may be true that inside the classroom the quality of the teacher has the greatest influence on student learning, the rest of the world outside of the classroom is much larger -- which is why testing experts like Harvard's Daniel Koretz warn:

A great many things other than the quality of schools influence educational achievement, and the impact of these noneducational factors can be huge... 

People routinely misinterpret differences in test scores, commonly attributing more to quality of education than they ought... 

Trends in scores over time, whether down or up, are often influenced by social factors and, in the case of seeming improvements, by inappropriate teaching to the test. Not all low scoring schools offer as weak an educational program as their scores might suggest. By the same token, if your neighborhood schools have high scores, that may mean less about the quality of their programs than you'd like. 

 The point to be taken here is that when we ask tests to be a window into the quality and quantity of student learning AND an educator's teaching, we are asking test scores to do something they can never do.